1. Field of the Invention
The present invention relates to a cable reel to be mounted on a steering device of automobile and, more particularly, to configure a large fixing case to be smaller in size and more attractive when providing a combination switch fixing area integrally with the fixing case of the cable reel.
2. Description of Background Information
On a steering device of automobile, a fixed case is provided which includes a protruding peripheral wall having an annular bottom wall. A rotor is rotatably within the inner periphery of the peripheral wall, and the rotor is provided with an annular upper wall. An annular cable housing is formed by intermitting the rotor in a rotatable manner with the fixed case, and a cable reel is mounted to house a flat cable in the annular cable housing in a spiral manner. A connector fixed on the internal end of the flat cable rotates with the flat cable in accordance with the rotation of the steering device which is fixed with the rotor, while a connector fixed on the external end of the flat cable is fixed on a fixed case which is fixed to the body of the automobile.
Conventionally, on a steering device, a combination switch mounting member is mounted separately from the cable reel, which is connected with a connector mounted on a fixed case of cable reel. However, in order to achieve a cost savings by reducing the number of components, a combination switch fixing area may be integrally mounted on the fixed case of the cable reel.
That is, as shown in FIG. 4 of the drawings, a connector housing 1b provides a combination switch mounting area on a peripheral wall 1a of a fixed case 1 having a bottom opening 1c. A flat cable 4 is inserted into the fixed case 1, and both terminals of the flat cable 4 are connected with connectors 2 and 3. The connector 2 is connected with the external end of flat cable 4 through the bottom opening 1c and then is inserted into a connector housing 1b. A case 5 having an annular bottom wall is interfitted and fixed within the bottom opening 1c of fixed case 1, and a movable rotor 6 is mounted in a rotatable manner in an upper opening of the fixed case 1. A rotor cover 7 is fixed to the rotor 6 after interfitting and fixing the connector 3, and a locking collar 8 is inserted in a rotatable manner into the bottom wall of case 5 and connected to the rotor 6.
With the structure described above, the number of components becomes greater, which causes such problems as increasing the number of assembling processes due to providing a bottom wall of case 5 and disposing the bottom wall of the fixed case 1 as a separate body. However, when the bottom wall of case 5 is made continuous to a peripheral wall by forming the same unitarily with the fixed case 1, it is necessary to provide a notch in the peripheral wall. When such a notch is provided, the connecting area between the flat cable and the connector become exposed on the peripheral wall side, causing possible intrusion of foreign matter thereinto, which gives rise to poor appearance and problems of impairing the performance of the cable reel.
In addition, as shown in FIG. 4, providing a connector housing 1b which is integral with a combination switch fixing area protruding from the peripheral wall 1a of fixing case 1 requires a larger external form for the fixing case 1, thereby causing the problem of requiring a larger installation space.
The present invention was made in view of the aforementioned problems, with the objectives of reducing the number of components and the assembling processes by forming the bottom wall of the fixed case unitarily and in one piece with the fixed case, and with an aim to avoid increasing the size of the fixed case.
The present invention provides a cable reel which includes a fixed case having a peripheral wall that protrudes from an outer periphery of an annular bottom wall, a moveable case having a peripheral wall that protrudes from the inner periphery of an annular upper wall, the fixed case and the movable case being interfitted in a rotatable manner and forming an annular cable housing space. The fixed case and the movable case house a flat a flat cable spirally in the cable housing. An opening is formed in a portion of the peripheral wall of the fixed case, and the connector housing is provided with a combination switch fixing area formed unitarily and in one piece on the bottom wall at a lower end of the opening area.
Additionally, a connector is connected with the terminal of external cable by welding at a vertical lower end of a bus-bar by laying narrow-strip bus-bars in parallel on an insulation board with the exposed ends of the flat cable conductors welded to the ends in the horizontal direction of each bus-bar. Accordingly, the welding area of the flat cable and the bus-bar of the connector is positioned at the opening, the welding area of the bus-bar and the cable is interfitted into the connector housing, and the opening in the peripheral wall of the fixed case is covered with a cover such that a continuous peripheral wall is provided having the same curvature as the cover. The cover is fixed to the peripheral wall by one of a lock connection and thermal adhesive.
With the cable reel of the present invention, a spirally-housed flat cable having both ends connected with connectors is inserted from an upper opening of a fixed case, a connector connected with an external peripheral end of flat cable is inserted downwardly in an opening provided on the peripheral wall of the fixed case and is interfitted with a connector housing protruding downwardly from the bottom wall. In such a manner, after a flat cable is housed in the fixed case, an opening in the peripheral wall of the fixed case is closed by a cover, thus covering a welded area between the flat cable and a bus-bar.
As mentioned above, because the bottom wall is formed unitarily and in one piece with the fixed case, a reduction in the number of components and assembling processes can be achieved compared with the situation where the bottom wall is provided as separate member.
In addition, since the opening of the peripheral wall is closed with a cover, and the cover does not protrude from the peripheral wall and is made to have a configuration that forms a part of the peripheral wall housing having the same curvature as that of the peripheral wall, the outer diameter of the cable reel does not increase. Furthermore, since the connector housing is formed unitarily and in one piece with the combination switch fixing area that protrudes downwardly from the bottom wall, it is possible to unitarily connect the combination switch fixing area without increasing the outer diameter of the cable reel.
In another aspect of the invention, a cable reel is provided that includes a fixed case having an annular bottom wall. The fixed case includes a peripheral wall that extends upwardly from an outer periphery of the annular bottom wall. A movable case is provided having an annular upper wall, and the movable case includes a peripheral wall that extends outwardly from the inner periphery of the annular upper wall. The fixed case and the movable case are configured to interfit in a rotatable manner and to form an annular cable housing space. A flat cable is spirally wound in the annular cable housing space, an opening is formed in a portion of the peripheral wall of the fixed case, and a connector housing is formed unitarily and in one piece with a combination switch fixing area on the bottom wall at a lower end of the opening area.
In a further aspect of the present invention, the cable reel includes a connector connected to the terminals of an external portion of the cable at a vertical lower end of a bus-bar. The connector may be connected to the terminals of the external portion of the portion of the cable by welding, and the welding may further include laying narrow-strip bus-bars in parallel on an insulation board with exposed ends of flat cable conductors welded to ends of each bus-bar in a horizontal direction. Additionally, the welding area of the flat cable and the bus-bar of the connector may be positioned at the opening, and the welding area of the bus-bar and the cable may be interfitted into the connector housing.
In other aspects of the present invention, the opening in the peripheral wall of the fixed case may be provided with a cover, such that a continuous peripheral wall is provided, and the cover may be provided to have a same curvature as the peripheral wall of the fixed case. Additionally, the cover may be fixed to the peripheral wall by one of a locking connection and thermal adhesive.